Impedance shaping for parallel operation of inverters in islanded AC microgrids

This paper proposes a new decentralized control strategy for parallel inverters operating in an islanded Microgrid. The proposed technique uses the Uncertainty and Disturbance Estimation (UDE) strategy in order to generate a virtual output impedance while keeping the voltage of the internal Elctro-Motive Force (EMF) source equal for all the inverters in the system. The system achieves accurate current sharing over a broad spectrum, which is proportional to the inverter capacity. Simulation results are provided to illustrate the performance of this method.¹